Once way to connect two or more wires is to strip the insulation of each wire and crimp, twist or strand the wires together. A number of devices and fasteners are currently available for fastening electrical conductors. Twist-on connectors, also known as spring connectors, typically comprise helically coiled wires for receiving twisted conductor wire ends. As the wire ends are inserted, the coil spring expands slightly as the twisted wire ends are inserted. One disadvantage in nearly all conventional twist on connectors is the limited range of wire diameters the connector can accommodate. Another disadvantage is that contact between the conductors is made before the conductors are inserted into the connector, thus exposing the technician to the possibility of sparking, electrical shock, short circuit or other electrical hazard.